297 research outputs found
Appraisal of herbicide doses in Bean-Coffee intercropping in two localities of the central plateau in Costa Rica
En dos localidades del Valle Central de Costa Rica (Cacao de Alajuela y Santo Domingo de Heredia) se evaluaron tres dosis de los herbicidas acifluorfén, alaclor, metabenzatiazurón, cianazina y diurón, en frijol (cv.Huetar) sembrado en la hilera de poda del cafeto (cv. Caturra). La cianazina eliminó el frijol y causó clorosis en los brotes del cafeto que se recuperó 20 días después de la aplicación. El diurón afectó negativamente al frijol y en forma leve lo hizo el alaclor sin que afectaran al cafeto. El acifluorfén y metabenzatiazurón afectaron levemente ambos cultivos, con recuperación del cafeto 20 días después de la aplicación. Las malezas presentes no afectaron los rendimientos de frijol debido a varios factores de manejo del cafeto que minimizan el problema de malezas en esta asociación. Los rendimientos de frijol fueron mayores en Santo Domingo, al parecer, el sistema de poda al cafeto aplicado en esta localidad influyó en estos resultados.Three doses of the herbicides acifluorfen, alachlor, methabenzathiazuron, cianazine and diuron were tested on common bean (Phaseolus vulgaris L.) cv. Huetar planted on the pruned coffee row (cv. Caturra) in two localities (Cacao de Alajuela and Santo Domingo de Heredia) of the Central Plateau in Costa Rica. The cianazine eliminated the beans and caused chlorosis to the coffee sprouts, which recovered 20 days alter its application. The diuron affected negatively the bean and lightly did so the alachlor, without affecting the coffee plants. The acifluorfen and methabenzathiazuron lightly affected both crops, although the coffee recovered 20 days alter the application. The present weeds did no affect the bean yield due to several management practices on the coffee, which lessened the weed problem in this intercropping system. The bean yield was higher in Santo Domingo and it seems that the coffee pruning system applied in this locality influenced these results.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Estación Experimental Agrícola Fabio Baudrit Moreno (EEAFBM
Appraisal of pre-emergent herbicides in beans (Phaseolus vulgaris L.) inter-cropped with coffee (Coffea arabica L.) in Alajuela, Costa Rica
En el cacao de Alajuela, Costa Rica, se evaluaron cinco tratamientos para combate de malezas en frijol intercalado al cafeto: acifluorfen (0,4 kg i.a./ha); alaclor (1,0 kg ia./ha); acifluorfen + alaclor (0,4 + 1,0 kg i.a./ha); alaclor + metabenzatiazuron (0,4 + 1,5 kg i.a./ha) y diuron (0,4 kg i.a./ha), en dos sitios dentro del mismo cafetal, uno con orientación de las hileras de cafeto de este a oeste y otro con orientación de las hileras de cafeto de norte a sur. El cafeto cultivar caturra posee una densidad de 6957 árboles por hectárea, con una separación entre hileras de 1,18 m y 0,90 m entre árboles. El sistema de poda por hilera, se realiza a 0,55 m del nivel del suelo, conservando las ‘bandolas’ y en un ciclo de tres alterno, con ‘Rock and Roll’. El frijol utilizado fue el Huetar. El periodo experimental comprendió del 18 de mayo al 29 de julio de 1987. No hubo diferencias significativas para el rendimiento en grano entre los tratamientos evaluados en los dos sitios; pero se observó una disminución del 51% en la producción cuando se intercaló con cafeto en hileras orientadas de norte a sur. Ninguno de los tratamientos presentó síntomas de fitotoxicidad en el cafeto. En el frijol el diurón (0,4 kg i.a./ha) presentó fitotoxicidad. Los síntomas consistieron en necrosis de los bordes de las hojas cotiledonales y reducción posterior del crecimiento y número de plantas a la Cosecha.Five pre-emergent herbicide treatments were evaluated, from May 18th to July 29th, 1987, on common bean (Huetar cultivar) inter-cropped with coffee (Caturra cultivar) in two sites within the same orchard, one oriented along the coffee rows from East to West and the other one from North to South, in El Cacao, Alajuela - Costa Rica. The treatments were: acifluorfen (0.4 kg a.i./ha), alachlor (1.0 kg a.i./ha), acifluorfen + alachlor (0.4+ 0.1 kg a.i./ha), alachlor + methabenzathiazuron (0.4+ 1.5 kg a.i./ha), and diuron (0.4 kg a.i./ha). The coffee orchard has a population density of 6957 plants per hectare, spaced at 1.18 m between rows and 0.90 m between plants. The row pruning system is done at 0.55 m from the ground, preserving the branches in a three year alternating cycle with ‘Rock and Roll’. There was no significant differences on grain yield among the treatments on both sites, although it was observed a yield reduction of 51% when the inter-cropping rows were oriented from North to South. None of the treatments showed phytotoxicity symptoms to the coffee. The diuron caused phytotoxicity to the bean plant and the symptoms included necrosis of the borders of the cotyledonal leaves and a reduction of growth and number of plants at harvest time.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Estación Experimental Agrícola Fabio Baudrit Moreno (EEAFBM
Mejoramiento de la fijación biológica del nitrógeno en el frijol
UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Estación Experimental Agrícola Fabio Baudrit Moreno (EEAFBM
Effective Rheology of Bubbles Moving in a Capillary Tube
We calculate the average volumetric flux versus pressure drop of bubbles
moving in a single capillary tube with varying diameter, finding a square-root
relation from mapping the flow equations onto that of a driven overdamped
pendulum. The calculation is based on a derivation of the equation of motion of
a bubble train from considering the capillary forces and the entropy production
associated with the viscous flow. We also calculate the configurational
probability of the positions of the bubbles.Comment: 4 pages, 1 figur
Genome-wide association analysis of more than 120,000 individuals identifies 15 new susceptibility loci for breast cancer.
Genome-wide association studies (GWAS) and large-scale replication studies have identified common variants in 79 loci associated with breast cancer, explaining ∼14% of the familial risk of the disease. To identify new susceptibility loci, we performed a meta-analysis of 11 GWAS, comprising 15,748 breast cancer cases and 18,084 controls together with 46,785 cases and 42,892 controls from 41 studies genotyped on a 211,155-marker custom array (iCOGS). Analyses were restricted to women of European ancestry. We generated genotypes for more than 11 million SNPs by imputation using the 1000 Genomes Project reference panel, and we identified 15 new loci associated with breast cancer at P < 5 × 10(-8). Combining association analysis with ChIP-seq chromatin binding data in mammary cell lines and ChIA-PET chromatin interaction data from ENCODE, we identified likely target genes in two regions: SETBP1 at 18q12.3 and RNF115 and PDZK1 at 1q21.1. One association appears to be driven by an amino acid substitution encoded in EXO1.BCAC is funded by Cancer Research UK (C1287/A10118, C1287/A12014) and by the European Community's Seventh Framework Programme under grant agreement 223175 (HEALTH-F2-2009-223175) (COGS). Meetings of the BCAC have been funded by the European Union COST programme (BM0606). Genotyping on the iCOGS array was funded by the European Union (HEALTH-F2-2009-223175), Cancer Research UK (C1287/A10710, C8197/A16565), the Canadian Institutes of Health Research (CIHR) for the CIHR Team in Familial Risks of Breast Cancer program and the Ministry of Economic Development, Innovation and Export Trade of Quebec, grant PSR-SIIRI-701. Combination of the GWAS data was supported in part by the US National Institutes of Health (NIH) Cancer Post-Cancer GWAS initiative, grant 1 U19 CA148065-01 (DRIVE, part of the GAME-ON initiative). For a full description of funding and acknowledgments, see the Supplementary Note.This is the author accepted manuscript. The final version is available from NPG via http://dx.doi.org/10.1038/ng.324
Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median ). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July
Enhanced production of multi-strange hadrons in high-multiplicity proton-proton collisions
At sufficiently high temperature and energy density, nuclear matter undergoes a transition to a phase in which quarks and gluons are not confined: the quark-gluon plasma (QGP)(1). Such an exotic state of strongly interacting quantum chromodynamics matter is produced in the laboratory in heavy nuclei high-energy collisions, where an enhanced production of strange hadrons is observed(2-6). Strangeness enhancement, originally proposed as a signature of QGP formation in nuclear collisions(7), is more pronounced for multi-strange baryons. Several effects typical of heavy-ion phenomenology have been observed in high-multiplicity proton-proton (pp) collisions(8,9), but the enhanced production of multi-strange particles has not been reported so far. Here we present the first observation of strangeness enhancement in high-multiplicity proton-proton collisions. We find that the integrated yields of strange and multi-strange particles, relative to pions, increases significantly with the event charged-particle multiplicity. The measurements are in remarkable agreement with the p-Pb collision results(10,11), indicating that the phenomenon is related to the final system created in the collision. In high-multiplicity events strangeness production reaches values similar to those observed in Pb-Pb collisions, where a QGP is formed.Peer reviewe
Measurement of D-s(+) product ion and nuclear modification factor in Pb-Pb collisions at root S-NN=2.76 TeV
Peer reviewe
One-dimensional pion, kaon, and proton femtoscopy in Pb-Pb collisions at root(NN)-N-S=2.76 TeV
The size of the particle emission region in high-energy collisions can be deduced using the femtoscopic correlations of particle pairs at low relative momentum. Such correlations arise due to quantum statistics and Coulomb and strong final state interactions. In this paper, results are presented from femtoscopic analyses of pi(+/-) pi(+/-), K-+/- K-+/-, K-S(0) K-S(0), pp, and (pp) over bar correlations from Pb-Pb collisions at root s(NN) = 2.76 TeV by the ALICE experiment at the LHC. One-dimensional radii of the system are extracted from correlation functions in terms of the invariant momentum difference of the pair. The comparison of the measured radii with the predictions from a hydrokinetic model is discussed. The pion and kaon source radii display a monotonic decrease with increasing average pair transverse mass m(T) which is consistent with hydrodynamic model predictions for central collisions. The kaon and proton source sizes can be reasonably described by approximate m(T) scaling.Peer reviewe
Measurement of azimuthal correlations of D mesons with charged particles in pp collisions at √s=7 TeV and p-Pb collisions at √sNN=5.02 TeV
The azimuthal correlations of D mesons with charged particles were measured with the ALICE apparatus in pp collisions at root s = 7 TeV and p-Pb collisions at root sNN = 5.02 TeV at the Large Hadron Collider. D-0, D+, and D*+ mesons and their charge conjugates with transverse momentum 3 0.3 GeV/c. The yield of charged particles in the correlation peak induced by the jet containing the D meson and the peak width are compatible within uncertainties in the two collision systems. The data are described within uncertainties by Monte-Carlo simulations based on PYTHIA, POWHEG, and EPOS 3 event generators.Peer reviewe
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